A fuel cell is a device which uses an electrochemical reaction to convert chemical energy stored in a fuel such as hydrogen or methane into electrical energy. In general, fuel cells include an anode to catalytically react with the fuel and a cathode in fluid communication with an oxidant such as air. The anode and cathode are disposed on opposing sides of an electrolyte material which conducts electrically charged ions therebetween. The electrolyte material and the design of the fuel cell determine the type and performance of the fuel cell. For example, Solid Oxide Fuel Cells (SOFC) utilize electrolytes made from ceramic materials and have high operating temperatures, in the range of 700-900 degrees Celsius.
SOFCs can be quite large, for example SOFC stacks typically include many individual fuel cells disposed between separators and compressed together in the stack to facilitate electrical conductivity across the SOFC stack. The individual fuel cells can have a large cross sectional area. Heating and/or cooling the SOFC stacks to and from the operating temperature of about 700-900 degrees Celsius can cause significant temperature gradients over the large cross sectional areas. Such temperature gradients can impart thermal stresses on the SOFC stack which can cause misalignment and/or distortion of the individual fuel cells. Such misalignment and/or distortion can degrade compression between the fuel cells thereby reducing the electrical conductivity across the SOFC stack and/or reducing the performance of the SOFC stack.